1. Field of the Invention
This invention relates to the use of conductive polymers in heaters.
2. Introduction to the Invention
Conductive polymers are well-known for use in electrical devices such as circuit protection devices and heating elements. Such elements, and compositions and processes useful for making such elements, are described in U.S. Pat. Nos. 3,179,544, 3,399,451, 3,793,716, 3,858,144, 3,861,029, 3,914,363, 4,017,715, 4,085,286, 4,095,044, 4,135,587, 4,177,376, 4,177,446, 4,223,209, 4,237,441, 4,272,471 4,304,987, 4,314,230, 4,315,237, 4,318,220, 4,317,027, 4,318,220, 4,327,351, 4,330,703, 4,388,607, 4,421,582, 4,517,449, 4,532,164, 4,543,474, 4,548,662, 4,654,511, 4,689,475, and 4,700,054 and in copending commonly assigned U.S. application Ser. Nos. 141,989, 784,288 (now U.S. Pat. No. 4,743,321), 938,659, 053,610 (now U.S. Pat. No. 4,777,351), and 119,618. The disclosure of each of these patents and pending applications is incorporated herein by reference.
Laminar heating elements are particularly useful for distributing heat uniformly over wide areas either by direct physical and thermal contact or through radiant heating. Devices comprising such heaters are described in U.S. Pat. Nos. 4,426,633, and 4,689,475, and in copending commonly assigned U.S. Application Ser. Nos. 818,844, 818,845, 818,846, 913,290, 75,929, and 89,093. The disclosure of each of these patents and pending applications is incorporated herein by reference.